Leigh C.P. Botly and Eve De Rosa, psychologists at the University of Toronto, say that the neurotransmitter acetylcholine is key to the process of feature binding, by which our brain combines all of the specific features of an object and gives us a complete and unified picture of it.
As part of the study, a group of volunteers participated in a feature binding task (choosing among various shapes and colors), with some of them being distracted throughout the duration of the task.
The researchers also developed a feature-binding task for rats (having them choose among variously scented food bowls) and treated some of the animals with the drug scopolamine, which temporarily blocks the effects of acetylcholine.
They found that patterns of behaviour were very similar in distracted humans and rats on scopolamine.
Both the drug treated rats and distracted humans had a decreased ability to complete the feature-binding task, although their ability to process just single features of an object (e.g. one specific color or odor) was not affected.
The authors note that "acetylcholine may provide the attentional 'glue' for feature binding".
Their findings could open the way to improved therapies for disorders like Alzheimer's disease.
The study is published in the November issue of Psychological Science, a journal of the Association for Psychological Science.